2.2: Get authorization

When your customer selects Klarna to pay, you need to use our JavaScript SDK to get authorization for the purchase.

In this step, you send all the necessary customer details for Klarna to assess and decide whether or not to accept this purchase. When the authorization is successful, you receive an authorization token as a response, useful for Step 3: Create an order.

The authorization is possible through the authorize() call happening on the client side.

Klarna.Payments.authorize(
  {},
  {
    billing_address: {
      given_name: "Alice",
      family_name: "Test",
      email: "customer@email.se",
      street_address: "Södra Blasieholmshamnen 2",
      postal_code: "11 148",
      city: "Stockholm",

If no billing or shipping address is provided, new Klarna customers have to manually enter their full billing address on the Klarna payment page. Providing the billing address in the authorize() call enables Klarna to prefill the signup form for new customers.

We recommend to avoid any delays or asynchronous operations (for example, sending calls to your backend) between the user clicking the Buy button and you calling authorize() . Longer delays or asynchronous operations between the actual user interaction and the authorize() call cause the browser to block the Klarna pop-up from opening.

To update the Klarna session, provide all necessary information when calling authorize() . If you need to update your backend session, we recommend doing so when the customer returns from Klarna's purchase flow.

In some cases, Klarna requires additional information about the customer and purchase. We recommend you send it in the authorize() call. For more information, see the Extra merchant data section.

Klarna uses all this information to make the risk assessment. To see what data you need per market and how to format it, check the customer data requirements.

During the authorize() call and until you receive the callback, Klarna runs a purchase flow that includes a risk assessment. You need to visually indicate to your customer that an ongoing process is happening. For a better user experience, we suggest:

• Avoiding another authorize() call (for example, disable the buy button)
• Showing your customer that the order is in progress (for example, show a loading spinner)
• Preventing your customer from changing the order or billing details (for example, lock the input fields on your page).

There are three potential cases that you need to handle based on the response:

• Success response: The purchase is approved.
• Fixable error response: The customer needs to adjust and try again.
• Error response: The purchase is not approved and you can't display Klarna as a payment option.

{
  "authorization_token": "0eb73d2c-d55a-5358-9080-ddc3903e3941",
  "session_id": "e4b81ca2-0aae-4c16-bcb2-29a0a088a35b"
}

If the response is approved: true , Klarna has approved the authorization for this purchase and as a response you will received the response including:

• approved , containing the authorization result. It's a boolean value that indicates approved or denied.
• show_form , showing the availability of Klarna as a payment option. It's a boolean value that indicates displayed or hidden.
• authorization_token , containing the token that allows you to place the order. This is only returned if it's an approved authorization.
• error , contanining details of potential error messages.

authorization_token  allows you to create an order for both scenarios, recurring and one-time payments. The token is valid for 60 minutes.

{
  "show_form": true,
  "approved": true,
  "finalize_required": false,
  "authorization_token": "0eb73d2c-d55a-5358-9080-ddc3903e3941"
}

{
approved: false,
show_form: true,
error: {
  invalid_fields: [
              billing_address.street_address
              billing_address.city
              billing_address.given_name
              billing_address.postal_code
              billing_address.family_name

An error message is displayed asking the customer to make corrections before you re-authorize the purchase. The error message points out which fields are incorrect.

It's also possible that the response is approved: false and show_form: true , but the callback doesn't include error . This means the customer has terminated a required interaction in the widget, such as authentication or sign-up flows. In this case, you should keep Klarna visible so that the customer can make another purchase attempt.

{
approved: false,
show_form: false
}

This negative response results from the pre-assessment that Klarna executes for the purchase.